Tamper-Resistant Storage Container

ABSTRACT

The present invention is directed to a tamper-resistant storage container. The storage container includes a container and lid portion having formed channels and surfaces along their perimeters configured to interlock securely to each other to attach the lid to the container. The lid includes at least one open area spanned by a breakaway stringer defining an area of weakness along a perimeter of the lid such that removing or attempting to remove the lid from the container breaks the stringer to provide a visible indication that the container has been opened or tampered with.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

The present invention relates generally to storage containers, and moreparticularly to sealable storage containers having a tamper-resistantfeature to indicate if the container has been opened since its originalsealing.

DESCRIPTION OF RELATED ART

Storage containers are commonly used for the storage and distribution ofnumerous products, including food products. For example, grocery storesoffer various pre-packaged food in storage containers having areceptacle portion covered by a lid that fits over the open top of thereceptacle. Grocery stores and other food merchants also offer freshlyprepared and ready to eat foods, placing those foods into storagecontainers for transport by the consumer. Merchants and consumers areconcerned with the safety of their food products, particularly in thecase of food that has been packaged into storage containers and placedinto areas accessible by the general public, such as in refrigerateddisplay chests in a delicatessen or grocery store. Because thosepackaged foods are accessible to the general public there is concernthat the storage containers may be opened either accidentally orintentionally, resulting in potential contamination or spoilage of thefood product within the container.

Various methods of sealing storage containers are known in the art, butthose known methods have numerous drawbacks. For example, storagecontainers are often wrapped with a cellophane band, ostensibly affixingthe lid to the receptacle portion of the container such that thecellophane band must be broken or removed to open the container so thatan un-banded container may indicate that the container has been openedsince its original sealing. This type of indicator is deficient,however, in that the consumer must first be aware that a cellophane bandshould even be present. In addition, because food storage containers aretypically made of a resilient, deflectable material, it is possible toremove and replace the cellophane bands onto the containers withoutbreaking or tearing them. Thus, sealing methods such as a cellophaneband do not provide a positive indicator of potential tampering with thecontainer and/or food product as is desired by merchants and consumers.

Other types of tamper resistant features have also been developed, suchas a security seal hindering access to the lid of a storage container.This type of security feature typically includes a break-away seal thatmust be removed in order to access and remove the lid from thecontainer. While generally effective, this additional seal method ofsecuring a container requires that one or more additional parts bemanufactured and installed on the container, thus increasing thecontainer cost and the labor cost to assemble the container with theseal.

SUMMARY OF THE INVENTION

The present invention is directed to a tamper-resistant storagecontainer comprising a container having an open top for receiving andstoring contents, with a lid configured to mate securely with thecontainer to seal the contents therein. The lid includes formed channelsextending around its outer perimeter, those channels and surfacesconform to and mate with similarly shaped channels and surfaces formedon the upper perimeter of the container. The engagement between thechannels and surfaces on the lid and container provide a seal betweenthe two. In addition, a protruding lip on the upper perimeter of thecontainer overlaps a setback portion of the lid to provide aninterference fit so that removal of the lid is very difficult withoutseverely deforming the container and/or lid.

The lid includes one or more tamper-resistant features, including openareas positioned along the perimeter, the open areas spanned by arelatively narrow stringer to provide one or more areas of weaknessaround the lid's perimeter. The stringers allow a portion of the lid tobe broken away to relieve the interference fit between the lid andcontainer at that area, thus allowing easy removal of the lid, with thebroken stringers providing a visual indication that the lid has beenremoved since the original sealing of the container. Because the lidfits so tightly to the container the force of removing or attempting toremove the lid from the container breaks the stringer to provide avisual indication that the container has been opened or potentiallytampered with since its original sealing.

Other variations and exemplary embodiments are also presented.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a tamper-resistant container with atamper-resistant feature intact in accordance with an exemplaryembodiment of the present invention.

FIG. 2 is a perspective view of the tamper-resistant container of FIG. 1with a tamper-resistant feature broken, indicating that the containerhas been opened.

FIG. 3 is an enlarged top view of a portion of the container of FIG. 1.

FIG. 4 is an enlarged top view of a portion of the lid of the containerof FIG. 1.

FIG. 5 is an enlarged top view of a portion of the tamper-resistantcontainer of FIG. 1.

FIG. 6 is a cross-sectional view of a corner of the container of FIG. 3.

FIG. 7 is a cross-sectional view of a side of the container of FIG. 3

FIG. 8 is a cross-sectional view of a corner of the container of FIG. 1showing a tamper-resistant feature intact.

FIG. 9 is a cross-sectional view of a corner of the container of FIG. 1showing a tamper-resistant feature broken with a tabbed portion of thelid pulled away from the container.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

The present invention is directed to a tamper-resistant container thatprovides a visible physical indication if the container has been openedafter its initial, original sealing. While the invention will bedescribed in detail below with reference to several exemplaryembodiments, it should be understood that the invention is not limitedto the specific configurations of these embodiments. For example,although the tamper-resistant container is described primarily in thecontext of consumer-sized food containers, the invention could equallybe used in connection with various other types of containers, such ascontainers for liquids or solids, or containers of other sizes. And,while the container in the figures is generally square in shape, theinvention may equally be implemented in containers of other shapes, suchas rectangular or round containers. In addition, although the exemplaryembodiments are described as embodying numerous features, one skilled inthe art will appreciate that the various features may be present invarious combinations in various embodiments of the invention.

Referring first to FIG. 1, an exemplary tamper-resistant storagecontainer is depicted generally by reference numeral 10.Tamper-resistant container 10 includes a container 12 configured toreceive and hold a desired contents, such as a food product, with a lid14 configured to attach securely to the container 12 to seal thecontents therein. Container 12 includes a bottom 16 with walls 18extending upwardly from the bottom to define a cavity 20 for receivingand storing any desired contents, such as solid or liquid food products.Corners 22 join walls 18 to form a smooth, integral transition betweenthe sides of the container, the corners 22 and walls similarly smoothlytransition to bottom 16. Walls 18 and corners 22 extend to an upper edge24, forming a perimeter around the top of container 12 for receiving alid.

Lid 14 is sized and shaped to cover the open top of container 12, with agenerally flat upper surface 26 extending to a perimeter 28 that isconfigured generally to the shape of the upper perimeter 24 of thecontainer. As will be described in more detail herein below, lid 14 andcontainer 12 each include similar interlocking channels and surfacesaround their perimeters such that the outer perimeter of the lid istightly engaged to the upper perimeter of the container so that the lidcannot be removed from the container without deforming the lid orcontainer material (providing evidence of tampering), or withoutbreaking a tamper-resistant security feature on the lid as will bedescribed in more detail herein below.

Looking still to FIG. 1, the outer perimeter of lid 14 is generallycontiguous, having at least one generally rectangular open area 30formed adjacent the outer edge of the lid. Open area 30 is spanned by arelatively narrow stringer 32 extending across the outermost side of theopen area. Open area 30 and stringer 32 in combination define an area ofweakness along the perimeter of the lid. Preferably, the area ofweakness is formed near a corner of lid 14, where a tab 34 protrudesfrom the lid to provide a convenient handhold grip for removing the lid14 from the container 12. Preferably, tab 34 extends approximately /4inch from the perimeter of the lid to provide an easy grasp to a user.It should be understood that while open area 30 and stringer 32 aredepicted and described, variations on this configuration are anticipatedby the present invention. For example, open area 30 could in fact be anarea defined by perforations in the perimeter of the lid such that theperforated area breaks away upon application of a removal force (i.e., aforce capable of removing the lid from the container) to the lid. Thearea of weakness thus comprises an area having a shear strength lessthan that of the remainder of the lid so that the area of weakness isthe first area to break when the lid is presented with a removal force.

FIG. 3 depicts a top view of lid 14 having a substantially flat uppersurface 26 with a stepped portion 27 extending adjacent the outerperimeter, providing a large stepped area near the corner of the lid.Open spaces 30 are positioned on opposite sides of the corner of thecontainer such that an area of weakness exists on each side of tab 34 onthe lid. FIG. 4 depicts lid 14 in place on a container such that theupper edge 24 of the walls 18 of the container are visible through theopen spaces 30.

Container 12 and lid 14 are preferably formed of plastic, using athermoform process wherein the raw plastic material is heated toapproximately 250 to 300 degrees Fahrenheit and formed onto a mold usingvacuum and air pressure. Most preferably, container 12 and lid 14 areformed of a transparent plastic having properties such that deformationor stress of the formed container or lid results in hazing, crazing,fogging, whitening, or other discoloration of the plastic material. Ofcourse, other materials known in the art may be used for the lid andcontainer, or the lid and container may be manufactured from dissimilarmaterials. These and other variations are within the scope of thepresent invention.

Looking now to FIG. 5, a top view of the tamper-resistant container ofFIG. 1 depicts the curved walls 22 of the container providing a smoothintegral transition between side walls 18. As also indicated in FIG. 5,a cross-sectional view of the curved corner portion of the containertaken along line 6-6 is depicted in FIG. 6, with a cross-sectional viewof the straight side of the container taken along line 7-7 depicted inFIG. 7.

Turning to FIG. 6, a cross sectional view of the corner of the containerof FIG. 1 shows lid 14 having a substantially flat upper surface 26 witha stepped portion 27 positioned atop the container 12, with the upperperimeter of the container and outer perimeter of the lid interlocked toform a tight seal between the two. Looking first to the upper perimeterof the container 12, corner wall 22 of the container extends upwardly toan outwardly projecting shelf 36 that quickly transitions to an upwardlyextending stub 38, with a recessed area in the upwardly extending stub38 forming an inwardly protruding tongue 40 in a portion of the stub.Upwardly extending stub 38 transitions to a substantially horizontal,outwardly extending upper wall 42, which quickly transitions todownwardly extending wall 44 and to outwardly protruding lip 46. Theconfiguration of the upper perimeter of container 12 thus provides atongue and groove arrangement to engage with similarly configured areason lid 14.

Looking still to FIG. 6, in a manner similar to that just described forcontainer 12, the substantially flat upper surface 26 of lid 14 stepsupwardly to stepped surface 27. Stepped surface 27 extends to upwardlyextending wall 48, which includes an inwardly extending channel 50approximately midway up wall 48. Wall 48 extends upwardly to upper wall52 which extends outwardly to the outer edge 54 of the lid, the edgeextending downwardly along wall 56 with a sharp step 58 extendingsubstantially horizontally and inwardly from wall 56, forming a channel60 in wall 56. A lower wall 62 extends generally downwardly from channel60 to tab 34 which provides an area for a user to grip and remove thelid.

As can be seen in FIG. 6, the upper perimeter of container 12 is shapedto conform closely to the outer perimeter of lid 14 such that the twointerlock to form a tight seal. More specifically, upwardly extendingstub 36 with inwardly protruding tongue 40 of the container conform andinterlock with upwardly extending wall 48 with inwardly extendingchannel 50 of lid 14. In addition, outwardly projecting shelf 36transitioning to upwardly extending stub 38 of the container conforms tothe stepped surface 27 transitioning to upwardly extending wall 48 ofthe lid, as does the upwardly extending stub 38 and transition tooutwardly extending upper wall 42 of the container conform to theupwardly extending wall 48 and transition to upper wall 52 of the lid.Also, looking closely to FIG. 6, sharp step 58 of the lid extendssubstantially horizontally and inwardly, undercutting the protruding lip46 of the container.

The interlocking channels and surfaces of the outer perimeter of the lid14 and upper perimeter of the container 12 as just described provide atight seal between the lid and container to securely engage the lid tothe container. In addition, as just described with respect to the cornerportion of the container, sharp step 58 of the lid undercuts theprotruding lip 46 of the container to provide an interference betweenthe two such that lid 14 may not be removed from the container 12without deforming the container or without breaking the tamper-resistantstringer as previously described.

Looking now to FIG. 7, a cross-sectional view of the side portion of thecontainer of FIG. 1 depicts interlocking channels and surfaces of theouter perimeter of lid 14 and upper perimeter of lid 20 in a mannersimilar to that as just described with respect to the cross-sectionalcorner view of FIG. 6. FIG. 7 shows lid 14 having a substantially flatupper surface 26 with a stepped surface 27 portion positioned atop thecontainer 12, with the upper perimeter of the container and outerperimeter of the lid interlocked to form a tight seal between the two.Wall 18 of the container extends upwardly to a slightly outwardlyprojecting shelf 37 that quickly transitions to an upwardly extendingstub 38, with a recessed area in the upwardly extending stub 38 formingan inwardly protruding tongue 40 in a portion of the stub. Upwardlyextending stub 38 transitions to a substantially horizontal, outwardlyextending upper wall 42, which quickly transitions to downwardlyextending wall 44 and to outwardly protruding lip 46. The substantiallyflat upper surface 26 of lid 14 steps to stepped surface 27 along theouter edge of lid 14. The stepped surface 27 extends to upwardlyextending wall 48, which includes an inwardly extending channel 50approximately midway up wall 48. Wall 48 extends upwardly to upper wall52 which extends outwardly to the outer edge 54 of the lid, the edgeextending downwardly along wall 56 with a gradual step 59 extendingdownwardly and inwardly to lower wall 62 which extends to an outer rim65.

As just described, the configuration of the side wall portions ofcontainer 12 and lid 14 are substantially similar to the correspondingcorner wall portions as described previously, with the exception of thesteepness of the step 58, 59 in the downwardly extending wall 56 of theouter portion of the lid defining the severity of the overlap with theprotruding lip of the container. In the corner wall portion as depictedin FIG. 6, the step 58 in the downwardly extending wall 56 of lid 14 isa sharp, substantially 90 degree horizontal step undercutting theprotruding lip 46 of the container. In the side wall portion as depictedin FIG. 7, the step 59 in the downwardly extending wall 56 of lid 14gradually eases into the area under the protruding lip.

As will be apparent to those skilled in the art, the sharp step 58 ofthe corner wall portion of the lid extending under the protruding lip 46of the container as depicted in FIG. 6 provides a positive engagementbetween the sharp step and lip such that the engagement makes itvirtually impossible to remove or disengage the lid from the containerwithout deforming or breaking either the lid or the container. Bycontrast, the gradually easing step 59 of the side wall portion asdepicted in FIG. 7 provides some interference to removal of the lid, butallows the lid to be disengaged without necessarily deforming orbreaking the lid or container. Thus, the combination of the sharp step58 on the corner wall portion of the container and the gradual step 59on the side wall portion of the container provides a secure seal betweenthe lid and the container that cannot be removed without breaking thetamper-resistant stringer portion of the lid, but, once broken, allowsthe lid to be removed without requiring unreasonable force.

As will be further apparent, the relative ease or difficulty in removingthe lid 14 from the container 12 may be adjusted by varying the amountof lid perimeter having a sharp step versus the amount of lid perimeterhaving a gradual step. For example, the exemplary embodiment as justdescribed includes sharp steps (as depicted in FIG. 6) positioned alongthe corner perimeter of the lid and at approximately the tangentialpoints at the intersection with the side walls 18 to the corners 22,with a gradual step (as depicted in FIG. 7) extending along the sideportion of the lid as seen in the cross-sectional views of FIGS. 4 and 7and as described above. By varying the length of lid perimeter having asharp step overlap, e.g., by extending the sharp step into the straightsidewall area, the engagement between the lid and the container iscorrespondingly increased such that the effort required to remove thelid is increased. Similarly, decreasing the length of lid perimeterhaving a sharp step overlap decreases the overall engagement between thelid and the container such that the lid is easier to remove from thecontainer. Of course, various combinations of sharp step overlap,gradual overlap, and no overlap may be combined to provide a desiredengagement between the lid and container and a corresponding requiredforce to remove the lid.

Additionally, the specific placement of a sharp step overlap region anda gradual overlap region along the perimeter likewise affects the forcenecessary to remove the lid. For example, a sharp step overlap along thestraight side of the container would result in a much more difficultremoval than that same overlap located at a rounded corner of thecontainer. Finally, the amount of the overlap between the sharp step 58and the lip 46 may be varied to increase or decrease the engagementforce—by varying the length of the sharp step 58 portion of lid 14, thelength of the protruding lip 46 portion of the container, orcombinations thereof. Preferably, the overlap between sharp step 58 andprotruding lip 46 is approximately 3/16 inch to approximately 7/32 inch.

Looking now to FIGS. 1-2 and 8-9 in conjunction, the operation of thetamper-resistant container will be described with reference to the twoperspective views of the tamper-resistant container 10 and twocorresponding cross-sectional views of the corner portion of thetamper-resistant container.

Looking first to FIGS. 1 and 8, with a new, unbroken lid 14 securelyengaged onto the container 12, the outer perimeter of the lid engageswith the upper perimeter of the container, with the channels andsurfaces formed in the outer perimeter of the lid engaging with thechannels and surfaces formed in the upper perimeter of the container,with the sharp step 58 of the lid under lapping protruding lip 46. Asdescribed in more detail previously, the engagement between the channelsand surfaces of the lid with the channels and surfaces of the container,in combination with the overlap between sharp step 58 of the lid andprotruding lip 46 of the container, provide a tight seal between the lid14 and the container 12 such that the lid cannot be removed withoutdeforming or breaking the lid and/or container. As depicted in FIG. 1,the new, unbroken lid is secured on the container with stringers 32intact and tab 34 in place at the corner of the tamper-resistantcontainer. The state of the lid and container as depicted in FIGS. 1 and8 corresponds to the condition of an originally sealed container—such asa food container into which food has been placed and the lid affixed andengaged. As is apparent in FIG. 1, the stringer 32 is unbroken and tab34 is positioned in its original, attached orientation.

Looking now to FIGS. 2 and 8, lid 14 has been disengaged from thecontainer by pulling tab 34 upwardly to: (1) break stringer 32 to allowthe tab to move, and (2) disengage the surfaces and channels of lid 14from the surfaces and channels of container 12. With tab 34 thus liftedand the corner portion of lid 14 disengaged from the corner portion ofcontainer 12, the force required to remove the lid has been decreasedsuch that the lid may be removed from the container by continuing topull upon tab 34 to pull the lid away from the container. Brokenstringers 32 and raised tab 34 provide a visual indication that the lidhas been removed since its original sealing, thus a consumer selecting acontainer in such a condition has an immediate visual indication thatthe container is no longer originally sealed and my have been tamperedwith.

As described previously, container 12 and lid 14 are preferably formedfrom a plastic material that hazes, crazes, or otherwise deforms ordiscolors upon being stressed. Thus, any attempt to open the containerby circumventing the tamper-resistant stringer and tab would result inyet another visual indication in the form of crazing to indicate thatthe container may have been opened or tampered with since its originalsealing.

Variations on the embodiments described herein are anticipated by, andwithin the scope of, the present invention. For example, while thetamper-resistant container in the exemplary embodiment depicted isgenerally square in shape, the invention described herein may beembodied in a tamper-resistant container of any shape, such as arectangular, circular, or oval container. Similarly, while thetamper-resistant container depicted herein includes a pair of open areas30 and stringers 32 defining areas of weakness adjacent a single cornerof the container, other numbers and configurations of that arrangementare contemplated by the present invention. For example, atamper-resistant container may include open areas and stringers adjacentevery corner of the container, adjacent only opposite corners of thecontainer, or positioned along a side of the container. Or in the caseof circular or oval containers, open spaces and stringers may bepositioned symmetrically or asymmetrically around the perimeter of thecontainer. These and other arrangements fall within the scope of thepresent invention.

The term “substantially”, “approximately” or other modifying term asused herein may be applied to modify any quantitative representationwhich could permissibly vary without resulting in a change in the basicfunction to which it is related. For example, lid 14 is described asbeing substantially flat, but may permissibly vary from thatqualification if the variance does not materially alter the capabilityof the invention.

While the present invention has been described and illustratedhereinabove with reference to an exemplary embodiment, it should beunderstood that various modifications could be made to this embodimentwithout departing from the scope of the invention. Therefore, theinvention is not to be limited to the specific embodiment described andillustrated hereinabove, except insofar as such limitations are includedin the following claims.

1. A tamper-resistant storage container, comprising: a receptaclecomprising a bottom with sidewalls extending upwardly to an upperperimeter, said bottom and sidewalls defining an inner cavity forreceiving and storing a contents; and a lid configured to mate with saidreceptacle to seal said contents therein, said lid comprising at leastone area of weakness positioned along a perimeter of said lid such thatsaid area of weakness will break prior to other portions of said lidwhen presented with a removal force to said lid.
 2. The tamper-resistantstorage container of claim 1, wherein said area of weakness comprises atleast one open area spanned by a stringer such that said stringer willbreak when presented with a removal force to said lid.
 3. Thetamper-resistant storage container of claim 1, comprising two areas ofweakness on said lid positioned along corresponding adjacent sidewallsof said receptacle.
 4. The tamper-resistant storage container of claim1, wherein said receptacle is substantially rectangular in shape andwherein said lid comprises at least two areas of weakness positioned onadjacent sidewalls on opposite sides of a corner of said receptacle. 5.The tamper-resistant container of claim 4, wherein said receptacle issubstantially square in shape.
 6. A tamper-resistant storage container,comprising: a receptacle comprising a bottom portion with at least onewall extending upwardly to an upper perimeter, said upper perimetercomprising at least one channel configured to mate with a like-shaped ona lid; and a lid comprising an outer perimeter, said outer perimetercomprising at least one channel configured to mate with said channel ofsaid receptacle such that said lid is securely held to said receptacle,wherein said lid comprises at least one area of weakness having a shearstrength less than a shear strength of a remainder of said lid.
 7. Thetamper-resistant storage container of claim 6, wherein said receptaclecomprises a protruding lip and wherein said lid comprises a steppedportion extending inwardly under said protruding lip such that saidstepped portion engages said protruding lip upon a removal force appliedto said lid.
 8. The tamper-resistant storage container of claim 7,wherein said stepped portion extends under said protruding lipapproximately at least 3/16 inch.
 9. The tamper-resistant storagecontainer of claim 6, wherein said area of weakness comprises an openarea spanned by a stringer.
 10. The tamper-resistant storage containerof claim 6, wherein said lid comprises a plurality of areas of weaknesspositioned around a perimeter of said lid.
 11. The tamper-resistantstorage container of claim 10, wherein at least two of said areas ofweakness are positioned on opposite sides of a corner of saidreceptacle.
 12. The tamper-resistant storage container of claim 6,wherein said receptacle is substantially circular in shape and whereinsaid at least one wall extends around a perimeter of said bottom. 12.The tamper-resistant storage container of claim 6, wherein at least oneof said lid and said receptacle are made of a material having propertiessuch that deformation discolors said material.
 13. A tamper-resistantstorage container, comprising: a receptacle comprising a bottom with atleast one sidewall extending upwardly to an upper perimeter, said bottomand sidewall defining an inner cavity for receiving and storing acontents, wherein said upper perimeter comprises at least one channelconfigured to receive a corresponding protrusion in a lid; and a lidconfigured to mate with said receptacle, said lid comprising an outerperimeter having a protrusion configured to mate with said channel insaid receptacle, wherein said lid comprises at least one area ofweakness positioned along a perimeter of said lid such that said area ofweakness will break prior to other portions of said lid when presentedwith a removal force to said lid.
 14. The tamper-resistant storagecontainer of claim 13, wherein said receptacle comprises a protrudinglip and wherein said lid comprises a step extending inwardly under saidprotruding lip.
 15. The tamper-resistant storage container of claim 14,wherein said step extends under said protruding lip approximately atleast 3/16 inch.
 16. The tamper-resistant storage container of claim 13,wherein said area of weakness comprises an open area spanned by astringer.
 17. The tamper-resistant storage container of claim 13,wherein said lid comprises a plurality of areas of weakness positionedaround a perimeter of said lid.
 18. The tamper-resistant storagecontainer of claim 17, wherein at least two of said areas of weaknessare positioned on opposite sides of a corner of said receptacle.
 19. Thetamper-resistant storage container of claim 13, comprising a pluralityof areas of weakness positioned around said perimeter of said lid. 20.The tamper-resistant storage container of claim 19, wherein said areasof weakness have a shear strength less than a shear strength of areas ofsaid lid not comprising said areas of weakness.